The instant invention relates to flare nut wrenches, and more particularly the instant invention relates to flare nut wrenches which include a non-slip feature.
With the conventional flare nut or tube nut wrench, there is a tendency for the wrench to slip if too much force is applied. This is because flare nuts are generally made of a relatively soft material, such as brass, so that excessive torque applied by a wrench to the nut causes the corners of the nut to round off, resulting in wrench slippage. Due to the configuration of conventional flare nut wrenches, excessive torque can also cause jaw slippage and spreading due to the open end configuration of the wrenches. Because of this slippage problem, manufacturers of flare wrenches frequently include disclaimers with their products since, from time to time, a person trying to tighten or release the flare nut is injured when a wrench slips.
The patent literature fails to disclose any patents which adequately address this problem. U.S. Pat. No. 3,668,950 discloses a structure in which the handle of the wrench presses against a pivotal jaw as the wrench is used. However, this patent is not particularly suitable for flare nuts.
U.S. Pat. No. 2,618,996 discloses a wrench specifically used for tightening nuts; however, the patent relies on a pair of opposed jaws rather than an open socket which is squeezed by a rigid prong projecting from the handle.
U.S. Pat. No. 2,655,064 discloses a handle with a prong and a pivoted jaw; however, the pivoted jaw is not pressured by the prong to squeeze the jaw tightly about a nut.
In view of the shortcomings of the prior art, there is a need for a wrench specifically suitable for flare nuts which is convenient to use and does not slip.